Headers, HF Cats, CAI to NPP Sound - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Adamadem · 12-17-2016, 02:41 PM

Hey Guys,

I've been doing research on the forum but only found a couple threads. What does out 1le sound like with headers, hf cats, cai to the npp system sound like. Hoping to avoid drone/rasp keeping the factory npp system.

cornerspeed92 · 12-17-2016, 06:22 PM

I can only respond to my high flow cat's as.......perfect. I would do it all over again!

Clarkstar · 12-17-2016, 06:24 PM

Sounds awesome! I love mine

Adamadem · 12-17-2016, 09:09 PM

In case I think it's too loud, could I add resonators to the exhaust. If so which type would fit? Also, I don't want to add an x-pipe or resonated x-pipe. I want to keep the stock h-pipe in place.

miller8907 · 12-17-2016, 09:50 PM

It sounds really good IMO. Its the setup I had before I tore everything out for turbos. With npp I just had a 3-way switch to have the npp flaps always open/always closed/or function like stock so when I wanted it quite I just closed the flaps and it was pretty tame. Open them up and get on the gas and it screams.

SSmitch · 12-18-2016, 08:10 AM

Quote:

Originally Posted by Adamadem

Hey Guys,

I've been doing research on the forum but only found a couple threads. What does out 1le sound like with headers, hf cats, cai to the npp system sound like. Hoping to avoid drone/rasp keeping the factory npp system.

When you add headers, HF Cats, CAI the NPP exhaust when in the closed position it will be louder than stock but it doesn't drone and sounds better, nothing annoying. IMO
When it's in the open position it changes to a really aggressive sound note, and it will drone some if you're running at a constant speed.

I've heard many combinations of exhaust set ups but this is my favorite sounding with the LS3, the only thing I plan to do different is add a 3 way switch so I can eliminate the loud start up.

This is a before and after having mods done.
100% Stock:

With Mods:

Olddudesrule · 12-18-2016, 09:41 AM

Absolutely perfect! I have Kook HFC's, Kooks LTH's and a CAI with NPP, and it has no drone, sounds great at idle, and fantastic at WOT.

Adamadem · 12-18-2016, 01:32 PM

Olddudesrule, do you mind posting a sound pic? I want to hear one with just those mods on it.

ZYBORG · 12-18-2016, 01:50 PM

I had SP 1 7/8 LTs with HF cats to NPP. It sounded pretty decent. Wish it would have been a little louder. I later deleted the HF cats and added 3" SW retrochamber quadtip catback. Not much of a difference in sound to be honest, just added drone.

PapaKlutch · 12-20-2016, 02:26 AM

Quote:

Originally Posted by Adamadem

Hey Guys,

I've been doing research on the forum but only found a couple threads. What does out 1le sound like with headers, hf cats, cai to the npp system sound like. Hoping to avoid drone/rasp keeping the factory npp system.

My 1LE with Z/28 cold air kit, ARH LT headers to HF cats, ARH X-pipe to factory NPP. Also has cam/heads, so a lope to the idle, but will give you an idea on volume. Fairly loud if NPP is open. I use the 3-way NPP switch for quiet time. But, open or closed there is no drone and no rasp.

Video on YouTube. Link below. Sub-woofer Recommended.

https://youtu.be/nIc-AXW3_aM

MBaseman · 12-21-2016, 12:34 PM

Another vote for perfect sounding, especially if you add an exhaust controlller for the NPP

Camaro Dude · 12-24-2016, 02:49 PM

Quote:

Originally Posted by Adamadem

Hey Guys,

I've been doing research on the forum but only found a couple threads. What does out 1le sound like with headers, hf cats, cai to the npp system sound like. Hoping to avoid drone/rasp keeping the factory npp system.

To kick things off, buy a quality 3-way controller from Forza, AND THEN, work your way front to back, and NOT rear of car to the front, or you will potentially miss the mark through bad hypothesis, and regret it once your out_of_pocket funded $$$ experiment ends.

Controller > CAI/TB/Intake > Headers > Cats > ......

cincidlr · 12-25-2016, 12:24 PM

have a 13 1LE w/ stainless works long tube header, CAI and the NPP. Removed the cats and lead the ecu remapped when the headers were installed and never disable the NPP. I love the sound! Reasonably quite under 3K but once you hit 3K, it ROARS! The majority of people who hear it, (keep in mind these are track people) luv it.

Adamadem · 01-11-2017, 08:52 PM

Just had the Headers and High Flow cats installed. Sounds great in terms of exhaust. Is it normal for Headers to make more noise in the cabin. It is not super loud but does increase with acceleration. A little music or opening the windows eliminates it. I think it is the pulse of the exhaust that I can hear.

12-17-2016, 02:41 PM	#1
Adamadem Drives: Saturn Join Date: Jul 2009 Location: Las Vegas Posts: 43	Headers, HF Cats, CAI to NPP Sound Hey Guys, I've been doing research on the forum but only found a couple threads. What does out 1le sound like with headers, hf cats, cai to the npp system sound like. Hoping to avoid drone/rasp keeping the factory npp system.

12-17-2016, 06:22 PM	#2
cornerspeed92 Drives: 2013 1SS 1LE Join Date: Jul 2012 Location: Colorado Posts: 4,188 View My Garage	I can only respond to my high flow cat's as.......perfect. I would do it all over again! __________________

12-17-2016, 09:50 PM	#5
miller8907 Drives: 2014 1SS/RS LS3 Join Date: Jul 2012 Location: Wisconsin Posts: 621	It sounds really good IMO. Its the setup I had before I tore everything out for turbos. With npp I just had a 3-way switch to have the npp flaps always open/always closed/or function like stock so when I wanted it quite I just closed the flaps and it was pretty tame. Open them up and get on the gas and it screams. __________________ 2014 1SS/RS LS3 AGP TT, Custom TSP Cam, 4L80E Swap 1/4 mile- 9.53 @ 145mph

12-18-2016, 09:41 AM	#7
Olddudesrule Resident nomad Drives: 2014 Summit White 1SS/1LE Join Date: Nov 2015 Location: Gilbert, AZ Posts: 1,765	Absolutely perfect! I have Kook HFC's, Kooks LTH's and a CAI with NPP, and it has no drone, sounds great at idle, and fantastic at WOT. __________________ Sold: 2007 Z06 2002 Viper GTS/ACR 2003 Z06 1965 FFR Cobra 2012 Nissan 370Z ADM LSA Stage II, Roto-Fab CAI, Kooks LTH/HFC's, Phastek CC, ported TB, Mishimoto radiator and oil cooler, BC Racing ER Series CO's, JPSS 32mm Black Magic rear bar, JPSS front inserts, R1 Concepts Premier slotted rotors/Goodrich SS lines, Schroth ASM harness, MGW flatstick, Brey-Krause HB, Tuned by NicD, at Cordes Performance Racing.

12-18-2016, 01:50 PM	#9
ZYBORG Lets roll... Drives: 14' Join Date: Jun 2014 Location: TX/S.FL Posts: 1,495	I had SP 1 7/8 LTs with HF cats to NPP. It sounded pretty decent. Wish it would have been a little louder. I later deleted the HF cats and added 3" SW retrochamber quadtip catback. Not much of a difference in sound to be honest, just added drone. __________________

12-17-2016, 06:24 PM	#3
Clarkstar Drives: 2013 1SS 1LE Join Date: Jun 2016 Location: Ixonia wi Posts: 1,456	Sounds awesome! I love mine

12-17-2016, 09:09 PM	#4
Adamadem Drives: Saturn Join Date: Jul 2009 Location: Las Vegas Posts: 43	In case I think it's too loud, could I add resonators to the exhaust. If so which type would fit? Also, I don't want to add an x-pipe or resonated x-pipe. I want to keep the stock h-pipe in place.

12-18-2016, 01:32 PM	#8
Adamadem Drives: Saturn Join Date: Jul 2009 Location: Las Vegas Posts: 43	Olddudesrule, do you mind posting a sound pic? I want to hear one with just those mods on it.

12-21-2016, 12:34 PM	#11
MBaseman Drives: 2015 2SS/RS/1LE Join Date: Jun 2015 Location: South FL Posts: 213	Another vote for perfect sounding, especially if you add an exhaust controlller for the NPP

12-25-2016, 12:24 PM	#13
cincidlr Drives: SS1LE Join Date: Apr 2013 Location: CINCINNATI Posts: 26	have a 13 1LE w/ stainless works long tube header, CAI and the NPP. Removed the cats and lead the ecu remapped when the headers were installed and never disable the NPP. I love the sound! Reasonably quite under 3K but once you hit 3K, it ROARS! The majority of people who hear it, (keep in mind these are track people) luv it.

01-11-2017, 08:52 PM	#14
Adamadem Drives: Saturn Join Date: Jul 2009 Location: Las Vegas Posts: 43	Just had the Headers and High Flow cats installed. Sounds great in terms of exhaust. Is it normal for Headers to make more noise in the cabin. It is not super loud but does increase with acceleration. A little music or opening the windows eliminates it. I think it is the pulse of the exhaust that I can hear.